1. Technical Field
The present invention relates to a liquid crystal display device, a method for manufacturing the liquid crystal display device, and an electronic apparatus.
2. Related Art
A known type of liquid crystal display device employs the technique in which an electric field is applied to the liquid crystal layer in the direction parallel to the surface of the substrate to control the orientation of the liquid crystal molecules. This type (hereinafter referred to as transverse electric field type) may be called IPS (In-Plane Switching) type or FFS (Fringe-Field Switching) type because of the form of the electrodes that apply the electric field to the liquid crystal layer. Transverse electric field type transflective liquid crystal display devices are studied in these years.
For example, JP-UM-A-2003-344837 discloses a transverse electric field type transflective liquid crystal display device in which circularly polarized light necessary for displaying black in the reflective mode is controlled by Δnd of the liquid crystal layer. Another transverse electric field type that displays black in the reflective mode by using a retardation layer formed on the liquid crystal layer side of the lower substrate is reported, for example, in “A Single Gap Transflective Display using a Fringe-field Driven Homogeneously Aligned Nematic Liquid Crystal Display”, M. O. Choi et al., SID05 DIGEST, pp. 719-721 (2005); “Voltage and Rubbing Angle Dependent Behavior of the Single Cell Gap Transflective Fringe Field Switching (FFS) Mode”, Y. H. Jeong et al., SID05 DIGEST, pp. 723-725; and “Optimization of Electrode Structure for Single Gamma in a Transflective IPS LCD”, Gak Seok Lee et al., SID05 DIGEST, pp. 738-741.
Unfortunately, the techniques described in the known documents above produce stains in the reflectively displayed black due to the wavelength dispersion characteristics of the materials of the liquid crystal and the retardation layer. It is therefore difficult to display high-contrast images. In addition, the devices of the above three non-patent documents have another retardation layer in the transmissive display region, and accordingly require a retardation film on the outer surface of the substrate. This disadvantageously reduces the viewing angle in the transmissive mode.
These problems occur not only in the transverse electric field type, but also in the vertical electric field type, in which an electric field is applied in the direction perpendicular to the substrate to control the orientation of the liquid crystal molecules.